Liquid crystal light valves in which the electro-optically active element is a liquid crystal composite are known. The composite comprises plural volumes or droplets of a liquid crystal material dispersed, encapsulated, embedded, or otherwise contained within a polymer matrix. Exemplary disclosures include Fergason, U.S. Pat. No. 4,435,047 (1984) ("Fergason '047"); West et al., U.S. Pat. No. 4,685,771 (1987); Pearlman, U.S. Pat. No. 4,992,201 (1991); and Dainippon Ink, EP 0,313,053 (1989). These light valves may be used in displays and window or privacy panels.
The prior art also discloses the concept of having a further material disposed between the polymer matrix and the liquid crystal material. See, for example, Fergason, '047; Fergason et al., U.S. Pat. No. 4,950,052 (1990) ("Fergason 052"); and Raychem, WO 93/18431 (1993) ("Raychem '431"). The purpose of having this further material has been variously stated as preserving the integrity of the volumes of liquid crystal material and for altering the electro-optical properties of the composite.
Improved processes for making composites, including an intervening further material or materials, are disclosed in copending, commonly-assigned applications of Reamey et al., "A Method of Making Liquid Crystal Composite", Ser. No. 08/217,581 (Attorney Docket MP1425-US1), filed Mar. 24, 1994; and Havens et al., "Liquid Crystal Composite and Method of Making", Ser. No. 08/217,268, (Attorney Docket MP1497-US1), filed Mar. 24, 1994; the disclosures of which are hereby incorporated by reference.
It is desirable in certain applications to include a dye or other component in the liquid crystal material of composites including such intervening further materials. However, where the intervening material is set in place by polymerization, the dye or other component may interfere with the polymerization. The present invention provides an effective process for making such composites.